This invention relates to the field of electric hand tools, and in particular, relates to a drywall sander, which can be used to sand in tight corners and in high places.
Presently, sanding of joint compound, sometimes called mud, which is used to cover nail heads driven into drywall and to cover tape which applied to drywall joints, is accomplished by either hand sanding or by use of a powered drywall sander. Sanding by hand is a tedious and time consuming endeavor. Hand sanders also tend to stick and tear the drywall paper and the sandpaper typically becomes clogged with drywall compound and becomes ineffective. Additionally, in order to sand ceilings or other high areas, a drywaller has to use stilts or erect scaffolding. Since there are safety concerns when using stilts or scaffolding, it would be more practical, safe, and convenient to be able to use a power sander which could reach high areas. Although existing power sanders are useful devices, there are some disadvantages associated with their use. One such disadvantage is that known power sanders are rotary type sanders that leave swirl marks in the joint compound. In order to remove these marks, hand sanding is required which negates some of the advantage of using the rotary type power sander. Another disadvantage with use of a rotary power sander is that care must be exercised because the power is such that it can easily damage the tape, the joint compound, or the underlying sheet of drywall. It is also known to use a power sander fitted to an extension pole or handle. However, it has been found that due to the weight of the rotary power sander, use of the extension becomes tiresome and difficult over extended periods of use. Further, prolonged use of a power sander fitted to an extension handle may result in serious injuries to the shoulders and the back of a drywaller.
Another problem associated with existing power sanders is that the motors which are used tend to wear out very quickly. This is due to drywall compound dust, which is abrasive, interacting with or being deposited on the motor brushes and bearing. The dust makes the motor work harder which generates more heat. The motor needs to be cooled to reduce the generated heat. This requires active cooling of the motor, which also increases the weight of the sander.
The present invention is designed to obviate these problems and overcome many of the disadvantages and shortcomings associated with present handheld and power drywall sanders. In particular, the present invention is a drywall sander which may be used to easily sand corners, restricted areas, and ceilings. Moreover, the drywall sander of the present invention, due to its maneuverability and light or reduced weight can be employed to sand corners and ceilings over longer periods of time.
In one form of the present invention, a drywall sander comprises a handle, a sanding head adapted to being reciprocated for back and forth motion, a power actuating means associated with the sanding head for reciprocating the sanding head, the power actuating means comprising a drive system having a tuned spring mass centering system, and a universal joint for connecting the handle to the power actuating means.
In another form of the present invention, a lightweight electrically operated drywall sander comprises a handle, a sanding head adapted to being reciprocated, a drive system associated with the sanding head for reciprocating the sanding head, and a universal joint for connecting the handle to the drive system for moving the handle relative to the sanding head into various positions.
Another form of the present invention is a drywall sander which comprises a handle, a sanding head adapted for reciprocating motion, a moving coil actuator for providing the reciprocating motion to the sanding head, a pre-loaded spring centering system for centering the sanding head prior to the sanding head being reciprocated, and a universal joint for connected the handle to the motor and for moving the sanding head relative to the handle.
In light of the foregoing comments, it will be recognized that a principal object of the present invention is to provide an improved drywall sander.
Another object of the present invention is to provide a drywall sander which is of simple construction and design and which can be easily employed with highly reliable results.
A further object of the present invention is to provide a drywall sander that has a reciprocating sanding surface in which a handle is connected to the sanding surface in such a manner that a pivot point is close to the drywall to be sanded in order to reduce the tendency of the sanding head to flip over while the sander is in use.
A still further object of the present invention is to provide a drywall sander which has a universal joint connection between a handle and a sanding head, with the universal joint connection providing movement of the sanding head relative to the handle in two planes while preventing rotational movement of the sanding head relative to the handle.
Another object of the present invention is to provide a drywall sander which is compact in design and light in weight which allows an operator of the sander to use the sander for long durations.
These and other objects and advantages of the present invention will become apparent after considering the following detailed specification in conjunction with the accompanying drawings, wherein: